I'm in no way experienced in the legal or marketing fields, so maybe I'm about to sound very naive. I mostly think of NDA's in this context in terms of keeping people quiet about material you give them early access to see until a certain date as to not screw up marketing campaigns. I wouldn't send an influencer inexperienced in the industry product so early you need an NDA to keep their mouths shut. Just wait until you're ok with them talking about it the instant it arrives on their doorstep. Edit: If we're talking about review copies, even with a lowest on the totem pole influencer so you probably want some way to keep them from putting up early access behind a paywall of some kind.
Now once it gets deeper then that, hey, NDA is understandable. Depending on the contents, of course.
Edit: After spending a little time thinking over basically any scenario besides the one I mentioned above, I'll answer the actual question of the topic with "yes". But some NDAs are fairer than others.